Switching power supplies employing inductive components have been in use for some time. Although most applications require constant output voltage (usually implemented through voltage feedback), some applications require a constant output current.
Standard practice for constant current outputs involves adding a resistor in series with the load to convert the output current into a voltage which can then be used as feedback. This approach, however, imposes a tradeoff between series resistor loss and feedback voltage magnitude, or dynamic range. A need exists for a method of detecting output current in switching power supplies which uses no series components.